Photonics Research Papers - Academia.edu (original) (raw)

In recent years, several New England projects have promoted professional development and curriculum design in optics and photonics. Funded in part by the Advanced Technological Education (ATE) program of the National Science Foundation (NSF), these projects have prepared middle and high school teachers, college faculty and career counselors from more than 100 New England institutions to introduce fiber optics, telecommunications and photonics technology education. Four of these projects will be discussed here: (1) The New England Board of Higher Education's (NEBHE) Fiber Optics Technology Education Project, (FOTEP) was designed to teach fiber optics theory and to provide laboratory experiences at the secondary and postsecondary levels. (2) Springfield Technical Community College's Northeast Center for Telecommunications Technologies (NCTT) is developing curricula and instructional materials in lightwave, networking and wireless telecommunications technologies. (3) The Harvard-Smithsonian Center for Astrophysics project ComTech developed a 12-week, hands-on curriculum and teaching strategies for middle and high school science and technology teachers in telecommunications and focused on optical communication (fiber optics). (4) NEBHE's project PHOTON is preparing middle, secondary and postsecondary instructors to introduce theory and laboratory experiences in photonics, including geometric and wave optics as well as principles of lasers and photonics applications.

- by
- •
- Optics, Curriculum Design, Fiber Optics, Telecommunications

The paper is a concise digest of works presented during the XIth Symposium
on Laser Technology (SLT 2016) [1]. The Symposium is organized
since 1984 every three years [2–8]. SLT 2016 was organized by
the Institute of Optoelectronics, Military University of Technology (IOE
WAT) [9], Warsaw, in cooperation with Warsaw University of Technology
(WUT) [10], Warsaw University [11], and Wrocław University of
Technology [12] in Jastarnia on 27-30 September 2016. Symposium
is a representative portrait of the laser technology research in Poland.
Symposium Proceedings are traditionally published by SPIE [13–21].
The meeting has gathered around 150 participants who presented around
120 research and technical papers. The Symposium, organized
every 3 years, is a reliable image of laser technology and laser applications
development in Poland at university laboratories, governmental
institutes, company R&D laboratories, etc. The SLT also presents the
current technical projects under realization by the national research,
development and industrial teams. The works of the Symposium, traditionally
are divided in two large areas – sources and applications.
The main topics of SLT were: laser sources in near and medium infrared,
picosecond and femtosecond lasers, optical fiber lasers and
amplifiers, semiconductor lasers, high power and high energy lasers
and their applications, new materials and components for laser technology,
applications of laser technology in mea surements, metrology and
science, military applications of laser technology, laser applications in
environment protection and remote detection of trace substances, laser
applications in medicine and biomedical engineering, laser applications
in industry, technologies and material engineering.

- by Ryszard Romaniuk
- •
- Materials Engineering, Photonics, Optoelectronics, Laser Technology

A wavelength multiplexing procedure for color transmission volume holograms of diffusing objects recorded in Bayfol® HX200 photopolymer is proposed. For the recording, three lasers of 442 nm, 532 nm and 633 nm, and a Spectralon® diffusing object were used for monochromatic and polychromatic calibration. Monochromatic calibration shows that the maximum index modulation obtained for each wavelength was not enough to give 100% efficiency, although the efficiency values achieved in the case of monochromatic recordings with diffusing objects were high, at around 90% for 633 nm and 532 nm recordings, and 60% for 442 nm. The efficiency values obtained for multiplexed holograms were 19.1% for the 442 nm hologram, 25.9% for the 532 nm hologram and 15.2% for the 633 nm.

- by Jesús Atencia
- •
- Photonics

A base-4 leading zero detector (LZD) design is proposed in this paper. The design is similar to the
approach originally proposed by V.G. Oklobdzija with a different technique. The circuit modules used in
the base-4 LZD approach are designed and several N-bit LZD circuits are implemented with a standard-
cell realization in the Taiwan Semiconductor Manufacturing Company (TSMC) 0.65um CMOS process.
The performance and layout area of the base-4 LZD realization is compared for implementations that
contain only 4-to-1 and 2-to-1 multiplexers

- by beni widhianto
- •
- Physics, Laser, Spectroscopy, Photonics

This paper reports on the use of cellulose paper simultaneously as electrolyte, separation of electrodes, and physical support of a rechargeable battery. The deposition on both faces of a paper sheet of metal or metal oxides thin layers with different electrochemical potentials, respectively as anode and cathode, such as Cu and Al, lead to an output voltage of 0.70 V and a current density that varies between 150 nA/cm 2 and 0.5 mA/cm 2 , subject to the paper composition, thickness and the degree of OH x species adsorbed in the paper matrix. The electrical output of the paper battery is independent of the electrodes thickness but strongly depends on the atmospheric relative humidity (RH), with a current density enhancement by more than 3 orders of magnitude when RH changes from 60% to 85%. Besides flexibility, low cost, low material consumption, environmental friendly, the power output of paper batteries can be adapted to the desired voltage-current needed, by proper integration. A 3-V prototype was fabricated to control the ON/OFF state of a paper transistor.

- by Bruno Bras
- •
- Optics, Medical Imaging, Fiber Optics, Telecommunications

Renewed technology has created a demand for foods which are natural in taste, minimally processed, and safe for consumption. Although thermal processing, such as pasteurization and sterilization, effectively limits pathogenic bacteria, it alters the aroma, flavor, and structural properties of milk and milk products. Nonthermal technologies have been used as an alternative to traditional thermal processing technology and have the ability to provide safe and healthy dairy products without affecting their nutritional composition and organoleptic properties. Other than nonthermal technologies, infrared spectroscopy is a nondestructive technique and may also be used for predicting the shelf life and microbial loads in milk. This review explains the role of pascalization or nonthermal techniques such as high-pressure processing (HPP), pulsed electric field (PEF), ultrasound (US), ultraviolet (UV), cold plasma treatment, membrane filtration, micro fluidization, and infrared spectroscopy in...

- by Sonia Khan
- •
- Photonics
- by Mario Armenise
- •
- Applied Mathematics, Physics, Acoustics, Optics

The maximum distance to which the secondary mirror can be moved with respect to its primary in a true Cassegrain telescope with limited image deterioration is found to be proportional to the fourth power of the focal ratio of the primary mirror. This limit is independent of all other parameters describing the system when the magnification of the secondary is greater than about 3.

- by Roger Clark
- •
- Mechanical Engineering, Optics, Medical Imaging, Fiber Optics

It is shown that the Fraunhofer diffraction pattern of a tilted aperture screen can be interpreted as a ' monocular view of the Ewald sphere. Two of those patterns recorded at opposite tilting angles are used to give a stereoscopic impression of the Ewald sphere. Experimental results are shown, and the approximations involved are discussed.

- by R. Bamler
- •
- Mechanical Engineering, Optics, Medical Imaging, Fiber Optics

An hybrid atomic force-scanning near-field optical microscope (AFM-SNOM) has been realized starting from a home-built AFM. The instrument uses a tetrahedral SiN tip for force and near field detection and is designed to provide, besides simple imaging, a full three-dimensional (3-D) mapping of force, friction and light intensity on the sample. High-resolution optical images of dielectric samples are presented together with curves describing the behavior of the collected optical intensity as a function of tip-object distance. AFM images and forcedistance curves are reported as well and are compared with those obtained from the optical channel. Subwavelength features of the samples can be easily appreciated in both kinds of images, and the refractive index of the object can be computed from the attenuation constant of the tunneling light detected by the tip, with the AFM curve providing a convenient way of detecting the contact point. The spatial resolution of this kind of measurement is far better than that obtainable with any other index-measuring device. Homogeneous glass samples as well as monomode channel waveguides were analyzed in our experiments. The refractive index of several different prisms, made either of BK7 (n = 1:519 at = 532 nm) or of SF58 (n = 1:932) glass, could be measured with our near-field technique. As for the channel waveguides, the accuracy of our measurements lets us detect their presence and lateral extension in the substrate but is not yet sufficient to allow the reconstruction of their index profile.

- by franco quercioli
- •
- Optics, Medical Imaging, Fiber Optics, Telecommunications

A theory is presented which relates the minimum detectable contrast level for an object in the presence of noise to the statistics of the speckle. Consideration is given to smoothing of the noise by multiple looks and by area. Measurements of the minimum detectable contrast are made for two types of speckle noise. First, a coherent, plane wave is added to an ideal diffuse wave and the threshold of detection is established as a function of the beam ratio. Secondly, these results are compared to the technique of speckle smoothing using an N-fold intensity superposition of fully developed theory is observed.

- by Nicholas George
- •
- Optics, Medical Imaging, Fiber Optics, Telecommunications

The propagation of a light beam through a photo-sensitive photopolymer Polyvinyl Alcohol/Acrylamide (PVA/AA), and the creation of self-written waveguides (SWWs), has received much attention. Here we explore the manufacture and characterization of SWWs in PVA/AA for applications at near infrared communication wavelengths 850nm and 1300nm. The SWWs are fabricated using visible light at wavelength 532nm. The insertion and optical loss of the SWWs at different wavelengths will be interrogated. An optical loss and attenuation profile is to be built up for each of the three wavelengths as they propagate down the resulting SWWs.

- by Derek Cassidy
- •
- Photonics, Polymers, Photopolymerization, Holography

We have demonstrated powerful new techniques for identifying the optical impairments causing the degradation of an optical channel. We use machine learning and pattern classification techniques on eye diagrams to identify the optical impairments. These capabilities can enable the development of low-cost optical performance monitors having significant diagnostic capabilities.

- by Joel Gannett and +1
- •
- Machine Learning, Pattern Recognition, Photonics, Support Vector Machines

We present a silicon-on-insulator (SOI) waveguide to fiber coupler fabricated using 248-nm-deep ultraviolet lithography. The loss of the taper structure is around 1 dB while the coupling loss from a lensed fiber into a 590-nm-wide SOI... more

- by Roel Baets
- •
- Photonics, Integrated Optics, Ultraviolet, Silicon on Insulator

A theory of the influence of measurement conditions on temperature measurement accuracy with infrared systems has been recently presented. A comparison study of the shortwave 13-5-µm2 and longwave 18-12-µm2 measuring IR cameras was conducted on the basis of this theory. The results of the simulations show that the shortwave systems in typical measurement conditions generally offer better accuracy in temperature measurement than do the longwave systems. Some experiments that use a commercially available IR camera were carried out to verify the theory. The results of these experiments and a discussion about the theory limitations are presented.

- by Krzysztof Chrzanowski
- •
- Mechanical Engineering, Optics, Medical Imaging, Remote Sensing

In the present study, we have investigated the effects of illumination intensity on the optical and electrical characteristics of the Al/CdFe 2 O 4 /p-Si/Al photodiode. A thin film of CdFe 2 O 4 was fabricated using the sol-gel spin coating method that allows good thickness control and low-cost manufacturing as compared to alternative techniques. The current-voltage (I-V) of the Al/CdFe 2 O 4 /p-Si/Al photodiode was measured in the dark and under different illumination intensities. The photocurrent increased with higher luminous intensity and its sensitivity has a strong dependence on the reverse bias rising from 1.08 * 10 −7 A under dark conditions to 6.11 * 10 −4 A at 100 mW/cm 2 of illumination. The parameters of the photodiode such as ideality factor and barrier height were calculated using the thermionic emission model. The ideality factor of the Al/CdFe 2 O 4 /p-Si/Al photodiode was found to be 4.4. The barrier height was found to be 0.88 eV. The capacitance-voltage (C-V) characteristics measured at different frequencies have strongly varied with frequency, decreasing with frequency. Consequently, the resulting interface density (it) value of the Al/CdFe 2 O 4 /p-Si/Al photodiode also decreased with higher frequency. Similarly, the fitted series resistance of the Al/CdFe 2 O 4 /p-Si/Al photodiode has declined with higher frequency.

- by Jabez McClelland
- •
- Applied Mathematics, Optics, Medical Imaging, Fiber Optics

Length Contraction is interpreted by human visual memory instead of Einstein's special relativity. The mechanism of an interactive observation by optical sensor or human eyes is studied. The concept "Same Time" in observation process is explained. As a result, in compliance with human visual memory, length contraction along the object can be recognized with different traveling speeds and angles. In addition, length expansion can also be observed along the direction away from the object.

- by Edward T . H . Wu
- •
- Visual Studies, Photonics, Light & Space (Art), Special Relativity

We model the double phase-conjugate mirror (DPCM) as a function of time, the average direction of propagation of the two beams forming the DPCM, and one transverse coordinate. Calculations show that the conjugation fidelity and reflectivity have different dependencies on the photorefractive coupling coefficient times length; the fidelity turns on abruptly with a threshold, whereas the reflectivity increases smoothly. The DPCM behaves as an oscillator at and above threshold: the time required for the reflectivity to reach the steady state dramatically slows down near threshold (like critical slowing down in lasers); above threshold the DPCM is self-sustaining even if the random noise terms used to start the process are set to zero. A decrease in the noise level improves the fidelity but increases the response time. The use of unbalanced input beam ratios results in asymmetric conjugation such that the fidelity obtained on the side of the weaker input beam is significantly reduced. The slowing down diminishes with increasing noise level or unbalanced input intensities.

- by Doruk Engin and +1
- •
- Applied Mathematics, Optics, Medical Imaging, Fiber Optics

A coherent processor is presented which is capable of performing a large class of 1-D linear space-variant operations. The only components of the processor are a 1-D input, a mask whose transmittance is specified by the desired linear operation, and an output plane. Compared with other 1-D processors, this processor has advantages of real space compactness and total elimination of vignetting. Experimental results are presented for the specific operations of convolution and spectrum scaling.

- by John F. Walkup
- •
- Mechanical Engineering, Optics, Medical Imaging, Fiber Optics

An experiment to investigate the potential of a laser-induced plasma method for determining concrete compressive strength was conducted by focusing a Nd:YAG laser on concrete samples with different degrees of compressive strength. This technique was developed in light of the role of the shock wave in the generation of a laser-induced plasma. It was found that the speed of the shock front depends on the hardness of the sample. It was also found that a positive relationship exists between the speed of the shock front and the ionization rate of the ablated atoms. Hence, the ratio of the intensity between the Ca(II) 396.8 nm and Ca(I) 422.6 nm emission lines detected from the laser-induced plasma can be used to examine the hardness of the material. In fact, it was observed that the ratio changes with respect to the change in the concrete compressive strength. The findings also show that the ratio increases with time after the cement is mixed with water.

- by Nasrullah Idris
- •
- Mechanical Engineering, Optics, Analytical Chemistry, Medical Imaging

An external reflection scanning near-field optical microscope with shear force regulation of the tip-surface distance is described. Near-field optical and shear force topographical images are compared for various samples. It is shown that the most important correlative relationships between these images can be deduced from symmetry considerations. The possibility of extracting additional information from the optical images is demonstrated on images of human blood cells.

- by Igor Smolyaninov
- •
- Mechanical Engineering, Optics, Medical Imaging, Fiber Optics

We present a model of energy consumption in IP networks. Using this model, we identify energy ldquohotspotsrdquo and estimate how energy consumption will grow with increasing network capacity. Todaypsilas Internet uses less than 1% of the available electricity supply. However, network energy consumption could grow substantially as access rates increase.

- by Kerry Hinton
- •
- Optics, Medical Imaging, Fiber Optics, Telecommunications

Techniques for active modulation and control of plasmonic signals in future highly-integrated nanophotonic devices have advanced rapidly in recent years, with recent innovations extending performance into the terahertz frequency and femtojoule-per-bit switching energy domains. As thoughts turn towards the development of practical device structures, key technologies are compared in this review and prospects are assessed for the future development of the field. Artist's impression of a hybrid opto-/electro-plasmonic chip combining microelectronic and photonic functionalities.

- by Nikolay Zheludev
- •
- Quantum Physics, Microelectronics, Nonlinear Optics, Nanophotonics
- by S. Tudisco
- •
- Physics, Photonics, Optical Communication, Quantum Cryptography

Interest in dynamic behaviour of carriers in organic materials is motivated by possible applications that include organic thin film transistors, organic electroluminescent (EL) devices, and organic photo-conductors. It can also provide insight into modelling of carrier transport and trapping in organic semiconductors and insulators Here, we employ advanced SHG technique to probe and visualize real carrier motion in organic materials. This is a time-resolved microscopic optical SHG (TRM-SHG) technique that allows direct and selective probing of dynamic carrier motion in organic materials. TRM-SHG experiments using pentacene field effect transistors (FET) revealed dynamic changes of SHG intensity profiles arising from pentacene. Carrier velocity in organic solids is thus determined from the visualized carrier motion. We anticipate that this direct visualization technique will find wide application in the illustration of space charge field formation in organic and inorganic materials, including biomaterials and polymers.

- by Takaaki Manaka
- •
- Optics, Technology, Quantum Optics, Spectroscopy

We report an ultracompact label-free biosensor that uses a vertical-cavity surface-emitting laser (VCSEL)-based measurement system for the characterization of biomolecular interactions. It consists of a VCSEL, a plastic guided-mode resonant filter, and two p-in detectors. The system has demonstrated very high sensitivity to molecules on top of the sensor.

- by Carlos Mateus
- •
- Biosensors, Photonics, Molecular Biophysics, Photodetectors
- by David Stodolsky
- •
- Mechanical Engineering, Optics, Medical Imaging, Fiber Optics

We present a discrete model for resonance in periodic dielectric slabs arising from the interaction of electromagnetic plane waves with guided modes at frequencies embedded in the continuum. Two infinite rows of interacting masses in the model support propagating and evanescent waves simultaneously. This allows for modes exponentially trapped near an obstacle at continuum frequencies. The discrete model manifests resonant transmission features of the periodic slab and it includes parameters of asymmetry that are connected to the detuning of the resonance. Moreover, resonant transmission in both systems is described by a rigorous universal formula that explicitly incorporates a detuning parameter.

- by Stephen Shipman and +1
- •
- Photonic Crystals, Light Scattering, Photonics, Scattering Theory

Most confocal microscopes do not produce images in real time with nonlaser light sources. The tandem scanning confocal microscope does produce such images but, because the pinhole apertures of the Nipkov disk must be placed far apart to reduce cross talk between neighboring pinholes, only 1% or less of the light available for imaging is used. We show that, by using aperture correlation techniques and relaxing the requirement to obtain a pure confocal image directly, one can obtain real-time confocal images with a dramatically increased (25% or even 50%) light budget.

- by Michal Kozubek
- •
- Optics, Quantum Physics, Medical Imaging, Fiber Optics

The integration of nanophotonics and atomic physics has been a long-sought goal that would open new frontiers for optical physics, including novel quantum transport and many-body phenomena with photon-mediated atomic interactions. Reaching this goal requires surmounting diverse challenges in nanofabrication and atomic manipulation. Here we report the development of a novel integrated optical circuit with a photonic crystal capable of both localizing and interfacing atoms with guided photons. Optical bands of a photonic crystal waveguide are aligned with selected atomic transitions. From reflection spectra measured with average atom number N ¼ 1:1 AE 0:4, we infer that atoms are localized within the waveguide by optical dipole forces. The fraction of single-atom radiative decay into the waveguide is G 1D /G 0 C(0.32 ± 0.08), where G 1D is the rate of emission into the guided mode and G 0 is the decay rate into all other channels. G 1D /G 0 is unprecedented in all current atom-photon interfaces.

- by Mahmoud Mohsen
- •
- Photonics, Multidisciplinary, Photonic Crystal, Nature Communications

The Photonics Explorer is an intra-curricular educational kit developed in a European project with a pan-European collaboration of over 35 teachers and science education professors. Unlike conventional educational outreach kits, the Photonics Explorer is specifically designed to integrate seamlessly in school curricula and enhance and complement the teaching and learning of science and optics in the classroom. The kit equips teachers with class sets of experimental components, provided within a supporting didactic framework and is designed for lower and upper secondary students (12‒18 years). The kit is provided completely free of charge to teachers in conjunction with teacher training courses. The workshop will provide an overview of the Photonics Explorer intra-curricular kit and give teachers the opportunity to work hands-on with the material and didactic content of two modules, ‘Light Signals’ (lower secondary) and ‘Diffraction and Interference’(upper secondary). We also aim to ...

- by Nathalie Debaes
- •
- Engineering, Optics, Photonics, Feedback

The Fraunhofer diffraction pattern of an aperture function, which can be described in terms of the superposition of a known aperture function with a half plane, has an amplitude distribution which is real along one direction and complex along the orthogonal direction. The real and imaginary parts of the amplitude distribution are related by Hubert transforms (dispersion relations). These disper sion relations can be used to arrive at the diffraction patterns of a variety of apertures having symmetry properties. Theoretical results are presented to illustrate the diffraction pattern of various apertures.

- by Rajpal S Sirohi
- •
- Optics, Medical Imaging, Fiber Optics, Telecommunications

Using our new negative Δ LC material in a fringing field switching (n-FFS) cell, we demonstrated superior performances to conventional positive Δ FFS (p-FFS) LCD in transmittance, viewing angle, cell gap sensitivity, gamma curve, while keeping a comparable operation voltage and response time. Therefore, n-FFS has potential to replace p-FFS for next-generation mobile displays.

- by Shin-Tson Wu
- •
- Condensed Matter Physics, Materials Science, Optics, Medical Imaging

Following the development and publication of the JCAMP-DX protocol 4.24 and its successful implementation in the field of infrared spectroscopy, data exchange without loss of information, between systems of different origin and internal format, has become a reality. The benefits of this system-independent data transfer standard have been recognized by workers in other areas who have expressed a wish for an equivalent, compatible standard in their own fields. This publication details a protocol for the exchange of Nuclear Magnetic Resonance (NMR) spectral data without any loss of information and in a format that is compatible with all storage media and computer systems. The protocol detailed below is designed for spectral data transfer, and its use for NMR imaging data transfer has not as yet been investigated.

- by asdf asdf
- •
- Mechanical Engineering, Optics, Chemistry, Analytical Chemistry

We present an extensive study of equalization enhanced phase noise (EEPN) in coherent optical system for all practical electronic dispersion compensation configurations. It is shown that there are only eight practicable all-electronic impairment mitigation configurations. The non-linear and time variant analysis reveals that the existence and the cause of EEPN depend on the digital signal processing (DSP) schemes. There are three schemes that in principle do not cause EEPN. Analysis further reveals the statistical equivalence of the remaining five system configurations resulting in EEPN. In three of them, EEPN is due to phase noise of the transmitting laser, while in the remaining two, EEPN is caused by the local oscillator. We provide a simple look-up table for the system designer to make an informative decision regarding practicable configuration choice and design.

- by Richard Schatz
- •
- Computer Science, Photonics

A simple apparatus for time-correla ted single photon counting (TCSPC) m easurements in the near-infrared (near-IR) region for scanning-type applications has been constructed and examined. The apparatus consisted of ® ve m ajor com ponents including a pulsed diode laser source (lasing wavelength 5 780 nm; rep etition rate 5 80 MHz; power 5 5 mW ; pulse width 5 150 ps), an integrated m icroscope, a large-photoactive-area avalanche photodiode (APD), a TCSPC PC-board including the electron ics, and a Windows-based software package for accu mulating the¯uorescen ce decay pro® les. The instrument response function (IRF) of this assembly was found to be 460 ps, which is adequate for measuring lifetim es with t f $ 500 ps. Due to the sm all size of the device, it also allowed implem entation into scanning experim ents where lifetimes were measured. To dem onstrate this capability, we scanned a three-well microscope slide containing a near-IR dye. The decay pro® le of the near-IR dye, aluminum 2,3-naphthalocyanine, was collected and analyzed to obtain its lifetime, which was found to be 2.73 ns, in close agreement with the literature value for this particular dye. In addition, a three-dim ensional plot showing the decay pro® les (tim e vs. photocounts) and scan position of aluminum 2,3-naphthalocyaninē uorescence was acquired by scanning the m icroscope head over this three-well glass slide. In the scanning m ode, the IRFs as well as the decays of the dyes were found to be very stable. The device dem onstrated a concentration detection sensitivity of 0.44 nM; however, the dynamic range was limited due to the slow tim e constant (passive quenching) associated with the APD.

- by Michael Wahl
- •
- Mechanical Engineering, Optics, Analytical Chemistry, Medical Imaging

Artur Dybko, Światłowodowy czujnik do pomiaru stężenia jonów hydroniowych, Praca dyplomowa magisterska, Instytut Podstaw Elektroniki, Politechnika Warszawska, 1990 (okładka, spis treści, dedykacja)
Wstęp,
Przegląd konstrukcji pH-metrów światłowodowych,
Wybór metody pomiarowyej,
Wyniki prac doświadczalnych,
Sugestie dalszych prac,
Dodatek chemiczny
Literatura.

- by Ryszard Romaniuk
- •
- Optical Engineering, Optical Fiber Communications, Electronics, Photonics
- by Andrew Greentree
- •
- Optics, Technology, Quantum Optics, Spectroscopy

The necessary and sufficient conditions on the gain of the linear amplifier are determined under which the light output exhibits sub-Poissonian photon statistics or squeezing. It is found that for these effects the intensity gain must not exceed 2 under any circumstances. It is also shown that there exists a weaker sufficiency condition on the gain above which all nonclassical features of the field disappear. This suggests the possibility that other quantum effects may persist in the intermediate, still unexplored, domain of operation of the amplifier.

- by Stephen Friberg
- •
- Applied Mathematics, Optics, Medical Imaging, Fiber Optics

Mean-variance analysis is described as a method for characterization of the read-noise and gain of focal plane array (FPA) detectors, including charge-coupled devices (CCDs), charge-injection devices (CIDs), and complementary metal-oxide-semiconductor (CMOS) multiplexers (infrared arrays). Practical FPA detector characterization is outlined. The nondestructive readout capability available in some CIDs and FPA devices is discussed as a means for signal-tonoise ratio improvement. Derivations of the equations are fully presented to unify understanding of this method by the spectroscopic community.

- by Roger Sperline
- •
- Mechanical Engineering, Algorithms, Optics, Analytical Chemistry

In a nonequlibrium plasma of a gas-discharge HgBr lamp, the terminal electronic state of the HgBr(B–X) radiative transition with a peak wavelength of 502 nm remains populated for a relatively long time and is repeatedly excited to the upper state in collisions with plasma electrons. This transfer of the HgBr molecules from the ground state X to the excited state B is the main mechanism of formation of the light-emitting molecules especially when the lamp is excited by double current pulses. According to our simulations, due to the electron-induced transitions between HgBr(X) and HgBr(B), the output characteristics of the DBD lamp operating in a double-pulse regime are better than those of the lamp operating in a single-pulse regime. In the considered case, the peak power is calculated to increase by a factor of about 2 and the lamp efficiency increases by about 50%.

- by Vadym Naumov and +1
- •
- Optics, Plasma Physics, Radiation, Laser Physics

We report 85 C continuous-wave electrically pumped operation of a 1528-nm vertical-cavity laser. An InP-In-GaAsP active region was wafer bonded to GaAs-AlGaAs mirrors, with a superlattice barrier to reduce defect density in the active... more

- by D. Lofgreen
- •
- Photonics, Optical physics, Electrical And Electronic Engineering, Superlattices

We foresee applications and interesting possibilities of incorporating the photonic crystals concept into superconducting electronics. In this paper, we present interesting features of the computed lower band structure of a nondissipative superconductor-dielectric superlattice using the two-fluid model and the transcendental equation [Pochi Yeh, Optical Waves in Layered Media, Wiley Series in Purl and Applied Optics (Wiley, New York, 1988)]. The necessary conditions for approximating the complex conductivity by an imaginary conductivity is derived and the feasibility of achieving the conditions are discussed. The superlattice dispersion obtained is similar to that of the phonon-polariton dispersion in ionic crystal. We found a nonlinear temperature-dependent "polariton gap" and a low-frequency (plasma) gap, and suggested the existence of a photon-superelectron hybrid around the polariton gap. The polariton gap may be observed in an infrared-microwave regime using a high-T-c, superconductor with sufficiently low normal-fluid relaxation time (approximate to 10(-15) s), and in an optical regime using lower penetration depth (approximate to 50 nm) and extremely low relaxation time (approximate to 10(-17) s).

- by Raymond Ooi
- •
- Photonics, Superconductors, Dielectrics, Superlattice
- by Walter Johnstone
- •
- Materials Engineering, Optics, Analytical Chemistry, Medical Imaging
- by Xianmin Yi
- •
- Applied Mathematics, Physics, Materials Science, Optics

New image processing methods and active photonics apparatus have made possible the development of relatively inexpensive optical systems for complex shape and object measurements. We present dynamic 360° scanning method for analysis of human lower body biomechanics, with an emphasis on the analysis of the knee joint. The anatomical structure (of high medical interest) that is possible to scan and

- by Bart Haex
- •
- Algorithms, Image Processing, Photonics, Data Visualization